1. Field of the Invention
The present invention relates to an image signal recording method and image signal recording unit, image signal reproducing method and image signal reproducing unit, image signal coding method and image signal coding unit, image signal decoding method and image signal decoding unit and image signal recording medium suitably used in recording a stereoscopic dynamic image signal in a recording medium such as a magneto-optic disk and magnetic tape for example, reproducing it to display on a stereoscopic display, transmitting it from the sending side to the receiving side via a transmission path and receiving it on the receiving side to stereoscopically display through a TV conference system, TV telephone system, broadcasting equipment and the like.
2. Description of the Related Art
FIG. 22 shows a principle of stereoscopic image. Generally a stereoscopic is a technique for bringing about a stereoscopic feeling in an image by giving different images to left and right human eyes by taking account of its parallax. In FIG. 22, an object 203 is projected on a screen 204 from each point of view of a left eye 201 and right eye 202 to obtain an image for left eye 201 and image for right eye 206. Accordingly, it becomes possible to stereoscopically show the object 203 as if it is floating out of the screen 204 even when the object 203 does not actually exist by giving the image for left eye 205 to the left eye 201 and the image for right eye 206 to the right eye 202 by some technique.
FIG. 23 shows an example of the stereo image thus obtained. As shown in the figure, the image for left eye 205 is disposed in odd fields and the image for right eye 206 is disposed in even fields, respectively, utilizing the interlace-scanned fields. A heavy interlaced structure corresponding to the parallax is seen in this stereo image. That is, the image for left eye 205 and image for right eye 206 which are originally a continuous one image (line) are shifted considerably to the left and right. Conventionally, the image thus produced has been recorded as it is in analog in a recording medium such as a magnetic tape, as shown in the U.S. Pat. No. 4,523,226 patented on Jun. 11, 1985 for example.
By the way, if a high efficient coding is applied to the image having a heavy interlaced structure such as shown in FIG. 23, a coding efficiency stagnates and an image quality drops because a very high frequency is concentrated around the edge of the object.
Accordingly, it is an object of the present invention to solve the aforementioned problem by providing means for efficiently coding even an image whose edge is heavily disturbed due to the interlacing, without degrading the image quality.